All multicellular algae are what?

Algae (singular: alga) are photosynthetic, eukaryotic organisms that do not develop multicellular sex organs. Algae can be unicellular, or they may be large, multicellular organisms.The multicellular algae develop specialized tissues, but they lack the true stems, leaves, or roots of the more complex, higher plants.

Explanation:

i would say it is

b) the inside picture would look at a very high temperature in a very low ph